Various types of guns are known in the art; among these, one specific category consists of the so-called “short recoil” guns.
Briefly, during the initial stages of firing, the bolt and the barrel recoil simultaneously for a stroke of several millimeters, thereby keeping the firing chamber locked. Subsequently, a proximal portion of the barrel is made to deviate by various expedients from the common stroke with the bolt to enable the latter to open the chamber and reload it with a new cartridge. Among the known locking systems one could mention, merely by way of example, the Browning, Glock or Sig-Sauer geometric type locks.
However, the known locks have the drawback that after an elevated number of firing cycles, the geometric coupling precision of the barrel, slide and components used to deviate the barrel, tends to rapidly decrease.
Moreover, from document DE19645681A1 a gun fitted with a transversal bar is known of which in a first functioning configuration of the firearm locks the barrel to the slide, and which in a second configuration releases the slide so as to allow its further rearward movement in relation to the barrel and to the gun frame.
However such earlier system also presents a variety of drawbacks. In particular, the oblique abutments acting between the transversal bar and the gun frame to block and to release the slide do not constitute a reliable technical solution, especially in quick fire, in that the transition of such bar between the described configurations is sudden and violent, subjecting said component to repeated stress. Moreover, the transversal bar remains totally inactive during the independent slide excursion, because it is released from the barrel in such a way as to completely insert itself in a special housing performed in the frame.
Besides, in the aforesaid earlier gun, the longitudinal translation of the slide is guided in an extremely imprecise manner; in fact, such movement is conducted by means of narrow contact areas of the slide on the barrel and on the frame, so that gliding of the slide does not remain accurately repeatable for a high number of cycles.
Lastly, in earlier documents DE29704123U1, U.S. Pat. No. 5,808,229A, GB673028A and U.S. Pat. No. 4,854,217A firearms with a tipping barrel are shown, which therefore envisage an inclination or lowering of the respective firing chambers during the various firing steps, and which are evidently lacking supplementary guide systems of the barrel in relation to the gun frame.